hey i have a stock rearend in my 99 trans-am, 6-speed, w/373 gears. ran an auto-x and was slowing for the end of the coarse.....when i down shifted to 1st, let out the clutch, the rear hopped real bad. now i have a bad thump, thump, thump sound coming from the rear of the car at 15mph-50mph then it quiets down. acceleration, deceleration, clutch in or out, it will make this noise.
thanks for any ideas,
ben